New soluble triphenylamine-based amorphous aromatic polyamides for high performance blue-emitting hole-transporting and anodically electrochromic materials

A newly 4-methoxy-substituted triphenylamine-containing aromatic diacid monomer, 4,4′-dicarboxy-4″-methoxytriphenylamine 2, with blue light (454 nm) fluorescence quantum efficiency 45% was successfully synthesized by the sodium hydride-mediated condensation of 4-methoxyaniline with 4-fluorobenzonitrile, followed by alkaline hydrolysis of the intermediate dicyano compound. A series of novel aromatic polyamides having strong fluorescence emissions in the blue region with high quantum yields up to 40% and one reversible oxidation redox couples at 1.08 V vs. Ag/AgCl in acetonitrile solution have been synthesized and characterized. They exhibited good thermal stability with 10% weight-loss temperatures above 460 °C under a nitrogen atmosphere with relatively high glass-transition temperatures (267–307 °C). All obtained polyamides revealed excellent stability of electrochromic characteristics, changing color from original pale yellowish to blue.